Preparation of 5-tert-butyl-metaxylene using a solid active clay catalyst

Abstract

Alkylation of metaxylene with isobutylene using a solid active clay catalyst produces 5-tert-butyl-metaxylene with high isomer selectivity with respect to 4-tert-butyl-metaxylene. The process is controlled to extend catalyst life and significantly reduce environmentally unfriendly waste.

1. A process to produce 5-tert-butyl-metaxylene comprising:
 a) adding a suitable alkylating agent to a mixture comprising active clay catalyst, a pressure-maintaining amount of non-reactive gas, and an effective amount of metaxylene into a reactor at reaction conditions comprising a temperature of at least 125° C. and a pressure of at least 450 kPa at an alkylating agent addition rate effective to form 5-tert-butyl-metaxylene;  
 b) recovering a portion of the 5-tert-butyl-metaxylene and a portion of the metaxylene without removal of the active clay catalyst from the reactor;  
 c) separating the 5-tert-butyl-metaxylene from the metaxylene;  
 d) recycling at least a portion of the separated metaxylene to the reactor.  
 
     
     
       2. The process to produce 5-tert-butyl-metaxylene of  claim 1 , wherein the active clay catalyst is an active dioctahedral smectite clay. 
     
     
       3. The process to produce 5-tert-butyl-metaxylene of  claim 1 , wherein the weight ratio of metaxylene to active clay catalyst in the mixture is greater than about 4:1. 
     
     
       4. The process to produce 5-tert-butyl-metaxylene of  claim 1 , wherein the alkylating agent addition rate is less than about 0.35 g/min for every 100 g of metaxylene in the mixture. 
     
     
       5. The process to produce 5-tert-butyl-metaxylene of  claim 1 , wherein the alkylating agent is isobutylene. 
     
     
       6. A process to produce 5-tert-butyl-metaxylene comprising:
 a) adding a suitable alkylating agent to a mixture comprising active clay catalyst , a pressure-maintaining amount of non-reactive gas, and an effective amount of metaxylene into a reactor at reaction conditions comprising a temperature of at least 125° C. and a pressure of at least 450 kPa at an alkylating agent addition rate effective to form 5-tert-butyl-metaxylene;  
 b) recovering a portion of the 5-tert-butyl-metaxylene, a portion of the metaxylene, and a portion of the active clay catalyst from the reactor;  
 c) separating the 5-tert-butyl-metaxylene from the recovered metaxylene and recovered active clay catalyst; and  
 d) recycling at least a portion of the recovered active clay catalyst and at least a portion of the recovered metaxylene to the reactor.  
 
     
     
       7. The process to produce 5-tert-butyl-metaxylene of  claim 6 , wherein the active clay catalyst is an active dioctahedral smectite clay. 
     
     
       8. The process to produce 5-tert-butyl-metaxylene of  claim 6 , wherein the weight ratio of metaxylene to active clay catalyst in the mixture is greater than about 4:1. 
     
     
       9. The process to produce 5-tert-butyl-metaxylene of  claim 6 , wherein the alkylating agent addition rate is less than about 0.35 g/min for every 100 g of metaxylene in the mixture. 
     
     
       10. The process to produce 5-tert-butyl-metaxylene of  claim 6 , wherein the alkylating agent is isobutylene. 
     
     
       11. A process to produce 5-tert-butyl-metaxylene comprising:
 a) adding a suitable alkylating agent to a mixture comprising active clay catalyst, a pressure-maintaining amount of non-reactive gas, and an effective amount of metaxylene into a reactor at reaction conditions comprising a temperature of from about 131° C. to about 156° C. and a pressure of from about 515 kPa to about 620 kPa at an alkylating agent addition rate of from about 0.11 g/min to about 0.35 g/min for every 100 g of metaxylene in the reactor;  
 b) recovering a portion of the 5-tert-butyl-metaxylene, a portion of the metaxylene, and a portion of the active clay catalyst from the reactor;  
 c) separating the 5-tert-butyl-metaxylene from the recovered metaxylene and recovered active clay catalyst; and  
 d) recycling at least a portion of the recovered active clay catalyst and at least a portion of the recovered metaxylene to the reactor.  
 
     
     
       12. The process to produce 5-tert-butyl-metaxylene of  claim 11 , wherein the active clay catalyst is an active dioctahedral smectite clay. 
     
     
       13. The process to produce 5-tert-butyl-metaxylene of  claim 11 , wherein the alkylating agent is isobutylene. 
     
     
       14. The process to produce 5-tert-butyl-metaxylene of  claim 11 , wherein the weight ratio of metaxylene to active clay catalyst in the mixture is about 9:1. 
     
     
       15. The process to produce 5-tert-butyl-metaxylene of  claim 11 , wherein the reactor pressure is about 585 psig. 
     
     
       16. The process to produce 5-tert-butyl-metaxylene of  claim 11 , wherein the alkylating agent addition rate is from about 0.13 g/min to about 0.29 g/min for every 100 g of metaxylene in the mixture. 
     
     
       17. The process to produce 5-tert-butyl-metaxylene of  claim 11 , wherein the active clay catalyst is an active montmorillonite clay.